Severe Weather Discussion for April 6, 2010.
– Severe thunderstorms are expected Tuesday afternoon and evening
across central and eastern Oklahoma. Primary threats are tornadoes,
damaging hail, and damaging winds.
– Chase Readiness is increased to Level 3.
No major changes on the 18z runs. GFS and NAM are a little closer on
the dryline location tomorrow afternoon and evening. The range is
still important as the NAM puts OKC in the threat area and the GFS
just east. There is really no reason to pick one model over the
other. It has to do with how they handle the lead shortwave trof and
how much energy hangs back in the base of the trof. The GFS has more
energy with the first system and lifts the surface low farther
northeast while the NAM holds it back some. The NAM does something I
think is weird with the 850mb winds, taking the strongly west and
scouring out the moisture, then backing them with some moisture return
along the dryline. This lowers CAPE values in eastern Oklahoma and
seems to be erroneous at this point. Just gonna have to watch and see
how things evolve tomorrow, can't say for sure if it is right. I have
seen the NAM do this before, but really don't remember the outcome. I
think the GFS ended up winning with the less veered flow.
SPC risk area looks good and see no reason to modify. I'm just not
sure on a moderate risk given the current questions. Models show deep
layer UVV's overspreading the dryline by late afternoon, indicating
deep convection prior to sunset. None of them set-off convection
prior to sunset, which I think is wrong. Either way, we'll know in
about 24 hours.
Current target area of Kingfisher to Enid remains the same. There may
be some modifications west/east depending on dryline location. If
anything, I'd expect a shift east, especially if the GFS ends up
Risk area for any part of OK/TX (valid: 04/06 Day 1):
Level 3 – Looking to head out on Tuesday. Target area is Kingfisher
to Enid, but may back-up east to Guthrie if the dryline moves like the
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